Mesenteric Peritonectomy as the Seventh Peritonectomy Technique in Cytoreductive Surgery for Peritoneal Surface Malignancies: A Propensity Score-Matched Analysis

Mesenteric involvement represents a major challenge in cytoreductive surgery (CRS) for peritoneal surface malignancies, historically regarded as a relative contraindication to complete cytoreduction. Mesenteric peritonectomy (MP), first described by Deraco et al. in 2009, selectively removes the peritoneal layer at the bowel-mesentery interface. Despite growing interest in its clinical application, robust outcome data from comparative studies remain lacking.

This retrospective, single-center study included 391 consecutive patients undergoing CRS-hyperthermic intraperitoneal chemotherapy at Fondazione IRCCS Istituto Tumori di Milano (2016-2024). MP was classified as partial, subtotal, or total. The primary endpoint was major postoperative morbidity (National Cancer Institute Common Terminology Criteria for Adverse Events grade ≥3); secondary endpoints included operative time, small bowel resections, completeness of cytoreduction, Comprehensive Complication Index, length of hospital stay, reoperation rate, and in-hospital mortality. A 1:1 propensity score-matched analysis compared subtotal/total MP patients with controls.

MP was performed in 76 patients (19.4%), predominantly for diffuse malignant peritoneal mesothelioma and serous papillary peritoneal carcinoma. In the matched cohort (n = 28 per group), MP was not associated with increased major morbidity (odds ratio 1.06; 95% confidence interval 0.37-3.06, p = 0.91), Comprehensive Complication Index, length of hospital stay, or reoperation rate. MP was associated with a longer operative time (+63 min; p = 0.005) and a higher likelihood of small bowel resection (odds ratio 6.4; 95% confidence interval 2.7-15.2; p < 0.001). No in-hospital deaths occurred in the MP group.

MP was a safe extension of CRS, as reflected by the high rate of complete cytoreduction. Despite increased surgical complexity, it was not associated with a significant increase in major morbidity, supporting its adoption at experienced centers.